city = input("请输入城市名:")
AQI = int(input("请输入空气质量指数AQI的值:"))
① AQI != -1:
if ②:
print(city,"的空气质量优良。")
③:
print(city,"的空气质量有污染。")
city=input("请输入城市名:")
AQI=④(input("请输入空气质量指数AQI的值:"))